Amrita Centre for Nanosciences and Molecular Medicine, Amrita Institute of Medical Sciences and Research Centre, Amrita Vishwa Vidyapeetham University, Kochi, India.
Tissue Eng Part A. 2012 Sep;18(17-18):1867-81. doi: 10.1089/ten.TEA.2012.0167.
Poly(caprolactone) (PCL) has been frequently considered for bone tissue engineering because of its excellent biocompatibility. A drawback, however, of PCL is its inadequate mechanical strength for bone tissue engineering and its inadequate bioactivity to promote bone tissue regeneration from mesenchymal stem cells. To correct this deficiency, this work investigates the addition of nanoparticles of silica (nSiO(2)) to the scaffold to take advantage of the known bioactivity of silica as an osteogenic material and also to improve the mechanical properties through nanoscale reinforcement of the PCL fibers. The nanocomposite scaffolds and the pristine PCL scaffolds were evaluated physicochemically, mechanically, and biologically in the presence of human mesenchymal stem cells (hMSCs). The results indicated that, when the nanoparticles of size approximately 10 nm (concentrations of 0.5% and 1% w/v) were embedded within, or attached to, the PCL nanofibers, there was a substantial increase in scaffold strength, protein adsorption, and osteogenic differentiation of hMSCs. These nSiO(2) nanoparticles, when directly added to the cells evidently pointed to ingestion of these particles by the cells followed by cell death. The polymer nanofibers appeared to protect the cells by preventing ingestion of the silica nanoparticles, while at the same time adequately exposing them on fiber surfaces for their desired bioactivity.
聚己内酯（PCL）因其良好的生物相容性而常被用于骨组织工程。然而，PCL 的一个缺点是其机械强度不足以满足骨组织工程的要求，生物活性也不足以促进间充质干细胞向骨组织的再生。为了纠正这一缺陷，本研究将纳米二氧化硅（nSiO2）添加到支架中，以利用二氧化硅作为成骨材料的已知生物活性，并通过纳米级增强 PCL 纤维来改善其机械性能。通过对纳米复合材料支架和原始 PCL 支架进行物理化学、力学和生物学评价，研究了它们在人骨髓间充质干细胞（hMSCs）存在下的性能。结果表明，当粒径约为 10nm 的纳米颗粒（浓度为 0.5%和 1% w/v）嵌入或附着在 PCL 纳米纤维中时，支架的强度、蛋白质吸附和 hMSCs 的成骨分化都会显著增加。这些 nSiO2 纳米颗粒直接添加到细胞中时，明显会被细胞摄取，随后细胞死亡。聚合物纳米纤维似乎通过防止细胞摄取纳米二氧化硅颗粒来保护细胞，同时充分暴露在纤维表面以发挥其所需的生物活性。
